Want To Find Cheap Acrylic 5 Or 10 Gal Tank

[sahmof2]

I have no room in my current sump due to large protein skimmer. I want to connect my current sump to another acrylic tank 5-10 gallon to use for deep sand bed and algae area for improved filtration. I could try to build my own but if I can purchase one reasonably, I would prefer to do this.